Protective shoe for tires.



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rrr oracion.

JAMES A. MURPHY, OF HOLYOKE, AND ROBERT J. HARRISON, OF CHIGGPEE FAILLS,

MASSACHUSETTS. ASSGNORS OF ONIE-THRD TO CHARLESAH. MORGAN, OF HOL- YonnMASSACHUSETTS.

PROTECTIVE SHOE FOR, TRES,

Ltldgl Si.

Specification of Letters Patent,

rarement nec. si, raie.

Application filed June 7,1910. Serial No. iuf.

To all whom it may camera:

Be it known that we, JAMES A. MURPHY and Ronnn'r J.' HAnRisoN, citizensof the United States of America, residing at Holyoke and Chicopec Falls,respectively, in the county oit Hampden and State ot' Massachusetts,have invented new and useful Improvements in Protective Shoes for Tires,ot' which the following is a specification.

This invention relates to pneumatic tires and especially to theconstruction of a pro? tective shoe for the inner tube of such tires tobe interposed between said tube and t-he inner surface ot' the tirecasing for the purpose et protecting the inner tube against puncturefrom any sharp object which ini lht penetrate the tread of the casing.

Yrotective shoes for the inner tubes oi pneumatic tires have been inadeheretofore,- one' type consisting of, an endless ring molded to contornito the interior surface vof the casing and the exterior surface of theinner t-ube, this shoe being of such diameter relative to the internaldiameter of the casing as to necessitate forcing it into the casingprior to the introduction of the inner tube, the idea being to malte thetit between the shoe and the casing so close that after the inner tubehas been inflated and the tire put into use, this shoe will not creepand thus set up a trictional action against. the outfr surface of thetulie and the inner surface of the casing. This structure is bot-hpractical and etlicient but it has been found in practice that theinternal diameter of casings of a given size of tire will vary sogreatly that the shoe whichl would lit tightly in one would be so loosein another casing as to render it liable to creep when in use. This hasmade it necessary to construct these endless protective shoes in a.great number of sizes which is a cmnlnercial handicap. Another type ofprotective shoe, designed to overcome this object-ion, has been inade inthe form of a broken ring having overlappingI beveled ends, this shoeAbeing vdependent upon t-he pressure of the inner tube, when inflated, tohold it with sufficient force against the inner circumference of the casing toprevent its creeping; but when the tire is in use, there isfinoreor. loss movement, one relativ" to the other, of the overlapping endsotmthis shoe thereby setting up frictional attion between the shoe andthe casing on the one side and the inner tube on the other. i

The object of the present invention is td i providen protective shoe ofthe character described in the 'torni of an endless ring" made up likethe tread portion of a casing of several layers of fabric and rubbervulcanized on a core to render the structure practically of ahomogeneous character, the two ends of the protective shoe being unit-edtogether to make an endless ring by means of a piece of relatively softrubber of such a compound as will, after vulcanization, render it toughand elast-ic, this unit-ing section of rubber being protected as far aspossible against puncture. By means of a protective shoe constructed in'this manner, 1t may be made as a continuous ring thereby avoiding anyfriction between the overlapping ends,

which is liable to occur when the shoe 1sinade as a broken ring, and yethaving the '75 extensible characteristic whereby the eXpansive action ofthe inflated inner tube will, owing to t-he yielding nature of the`uniting rubber section, distend the protective shoe forcing it intosuch intimate contact with the inner surface of the easing as topreventits creeping.

The invention is clearly illustrated in the accompanying drawing, inwhich,-

Figure l is a side elevation of the shoe S5 showing the unitingextensible section and one manner of protecting it, bycarrying one orino",e layers ol fabric offwhich the shoe is made loosely over thesection. F ig. 2 is a cross sectional view taken through the elasticunitingl section of the shoe, substantially on line 2 2, Fig. 1. This`view also shows, in section, the overlapping ilap of fabric. Fig. 3 is asectional elevation taken at right angles to Fig. 2 (that is in theplane ot the 95 shoe) and shows the method of inserting the elasticsection to unite the two ends of the shoe; it also shows how one or morelayers ot the fabric are carried over outside oi the elast-ic section toprotect the saine. as far as loo possible, against puncture. Fig. fi isa sec tional view like Fig. 3, but showing the elastic section locateddiagonally of the shoe, instead of radially, as in the preeledingfigures.`

Referring now to the drawings, a, Fig. 1, indicates the protective shoeas a whole; is the elastic section constituting anwintegral lil L theshoe and serving; to unite the two entsthereof. The layers of fabric ofwhich the. shoe is mede up are indicated by which, es nsnel in thisparticular type'oi shoe, are of ebric having e layer oi= raw ibenrolleci" into the surface thereof, con ting what' is termed frictioncloth, Wliielrbeiug out to the proper shape, will be iorine into a shoeof the desired thick ness by superposing one layer over another, thusbuiltling theshoe up on e core. The opposite ends of these pieces offabric (io not quite meet when laii up on the core, and to unitetheragrioiis'leyersot" fabric at the encis are-left yseparat- 1 for ashort dis# tsi'ice enti the'iuibber` section' 1b is formed byintrozluoing between 'the seperated ends of the fabric. as at. d Figs'.3 and afg, sheets of raw rubh fosueithickness that when pressed togit erand-vulc`anized, they will constitute e uniting medium for the twoendsof the shoe. These sheetsfo rubber, as is Well knovirnbeeome, under theeffect of vulcanizationse homogeneous mass and the extremiies ot the'rubber sheets introduced between the layers of. iebric will becomeadherent to the febrio'upon vuleanizetion. In this wey, tbe twoendso theshoe (which in itseli is inextensiblerlxlvviil be united by a. seoi tionwhich is readily' extensible but Whioh forms part of the shoe itself.For the purpose of protecting this more or less vulnerable part of theshoe occupied by the eittensible section b one or more layers of thet'ebrio are out long* enou h so that they may exten over this extensib esection, as shown e in Figs. 2 and 3. Another wey of protect-ing thisvulnerable 'part `oit the shoe against puncture consists in the'location of the extensible section b diagonally in Vthe body of theshoe, as shown in Fig. 4, it being apparent that when this section islocated thus, the area of unprotected surface' ofthis section would becomprised yWithin the two dotted lines 7 on saicl lign-re. When the shoeis mede as shown in Fig. the vulnerable aree of the section b is soreduced as to reni le? unnecessary to protect it in the men-i :eer shownin Fig. 3 by carrying' one or more thicknesses et the fabric e over seidaree.

sessi The heitere of the stmetnreis suoli .that it the shoe were,foundfto--be even a triegreter in iiiemeter their the.v internaldiemeter of the casing', the'extensible seo'tion thereof will be founcito be also suciently eomprsible to ermit the'shoe' to be forced into thecasingin proper 1position, the strueture thus being adapted to titcasings 'which 'the ring clie.,f ;onetlly7 to the radius of the latter,whereby the extremities of the ring may extend over and under seidextensible section.

' 2. A protective shoe consisting of :i ring comprising layers of`inertensible fabric anti rubber molded to fit the exterior periphery ofthe inner tube of a pneumatic tire` e portion of the body of the ringconsisting 'of elastic rubber whereby the ring; as a Whole may yieldradially, the ends ot said eXtensible section' being overlaid Aby theends o the fabric and made permanently adherent-wt thereto.

3. A protective shoe consisting of a concavo-convex ring,r ofinextensible materiel to t the exterior periphery lot the inner tube ofa pneumatic tire, said ting having a seotion or" 'rubber in; )rtecltherein whereby the ring may yield radially, seid rubber sectionconstituting s part of the body of the shoe the ends of the latter beingsplit to receive the end of said extensible rubber section, the

latter being mede permanently adherent to the ends' of the shoe.

JAMES A. MURPHY. ROBERT J. HARRSON.

-Witnesses1 i 1 JAMES J. QCONOR, EATRICK H. SHEEHAN, .l r.

